Optimizer & Options

BooleanExpressionOptimizer is the facade entry point: it parses, runs the rewrite pipeline, routes minimization by variable count, verifies the result equivalent to the input, and returns an OptimizationResult. Every example here is asserted in LogicalOptimizer.Tests/Documentation/DocExamplesTests.cs.

Basic optimize

using LogicalOptimizer;

var optimizer = new BooleanExpressionOptimizer();
var result = optimizer.OptimizeExpression("a & b | a & c", includeMetrics: true);

Console.WriteLine(result.Optimized);            // a & (b | c)
Console.WriteLine(result.CNF);                  // a & (b | c)
Console.WriteLine(result.DNF);                  // a & b | a & c
Console.WriteLine(string.Join(", ", result.Variables));  // a, b, c
Console.WriteLine(result.MinimizationStatus);   // MinimalProven
Console.WriteLine(result.IsEquivalent());       // True (verified against the input)

More rewrites, all verified equivalent to their input:

Input Optimized
(a \| b) & (a \| c) a \| b & c
!(a & b) !a \| !b
a & b \| !a & c \| b & c a & b \| c & !a (consensus)
a & 1 \| b & 0 a (constants)

OptimizationOptions

OptimizeExpression(expression, OptimizationOptions) gives fine-grained control. Presets: OptimizationOptions.Default (the standard path) and OptimizationOptions.Everything (also computes the advanced form and both truth tables). Notable members: ComputeCnf, ComputeDnf, ComputeAdvancedForms, IncludeMetrics, IncludeDebugInfo, IncludeTruthTables, CnfMode, Budget (ResourceBudget), CancellationToken, and EnableAigRewriting.

var everything = optimizer.OptimizeExpression("a & !b | !a & b", OptimizationOptions.Everything);
Console.WriteLine(everything.Advanced);              // a XOR b
Console.WriteLine(everything.OptimizedTruthTable);   // full truth table (not null)

AIG rewriting is on by default since v3.0

OptimizationOptions.EnableAigRewriting defaults to true in v3.0 (it was opt-in in 2.5). On the default path the optimizer computes one extra candidate — a DAG-aware And-Inverter-Graph cut rewrite — and adopts it only when it is both verified equivalent to the input and strictly cheaper by the cost metric. So the default output may now be a smaller multi-level form than before v3.0, and it can never be worse.

To restore the exact pre-3.0 output, turn the flag off:

// Default (v3.0): AIG rewriting enabled.
Console.WriteLine(OptimizationOptions.Default.EnableAigRewriting);  // True

// Opt out — restores the pre-3.0 two-level/multi-level result.
var pinned = optimizer.OptimizeExpression("(a & b) | (a & c) | (a & d)",
    new OptimizationOptions { EnableAigRewriting = false });
Console.WriteLine(pinned.Optimized);   // a & (b | c | d)

Both paths stay equivalence-verified; the only difference is whether the extra AIG candidate is allowed to win.

OptimizationResult fields

Besides Optimized / CNF / DNF / Advanced / Variables, the result carries MinimizationStatus (SOP/Optimized/DNF provenance) and CnfMinimizationStatus (equivalent-CNF/POS provenance — reported separately, Heuristic for CnfMode.Tseitin where two-level minimality does not apply), both explained in Operation contracts & statuses; CnfStatus / DnfStatus (ComputationStatus), optional Metrics (OptimizationMetrics: node counts, iterations, applied rules, elapsed time, convergence trace, allocated bytes), optional OriginalTruthTable / OptimizedTruthTable, DebugInfo, and the IsEquivalent() / CheckEquivalence() self-checks.

Quality analysis

OptimizationQualityAnalyzer turns a result into a compression/complexity report:

var r = optimizer.OptimizeExpression("a & b | a & c", new OptimizationOptions { IncludeMetrics = true });

var metrics = OptimizationQualityAnalyzer.AnalyzeOptimization(r);
Console.WriteLine(metrics.LiteralCount);   // 3
Console.WriteLine(metrics.OperatorCount);  // 2

Console.WriteLine(OptimizationQualityAnalyzer.GenerateQualityReport(r));
// === OPTIMIZATION QUALITY REPORT === ... compression ratio, optimality score, applied rules

Next steps

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